1. Field of the Invention
The invention relates to a grid flap, especially a grid flap for filling devices or scales, used in the field of food technology.
2. Description of the Related Art
For filling devices and scales, tanks and containers are known, which often comprise synchronously operated opening flaps. Depending on the product requirement, such opening flaps can be designed as grid flaps. This is especially advantageous, if the product to be filled or weighted has a sticky texture. In such a case, surfaces of members, which get in contact with the product, should be kept as small as possible to prevent adhesion.
By providing a flap with a plurality of braces arranged next to each other or on top of each other, it is possible to fulfill the above-mentioned requirements.
From the state of the art, such grid flaps are already known. Those can consist particularly of two sheet metal plates, a grid for pouring is jammed between them. A further known embodiment of the grid flaps relates to those which comprise a frame made of plastic, over which a wire netting is bent. For better fixation of the grid on the frame made of plastic, the plastic is molten at respective positions to which the wire netting is then pushed.
A serious disadvantage when using plastic is, that for example crystalline products lead to an abrasion of the plastic surface, that is why plastic residues can get into the food products. Further, parts made of plastic quickly become fragile and underlie deformations. This is especially valid if it is tried to clean the parts made of plastic with high temperatures, practically disabling hygienic process conditions.
Although both above-described types of grid flaps are often only used in filling devices or scales for microbially relatively immune food, wherein the requirements for hygienic design are relatively low, an optimal food safety can be guaranteed only then, if the member is fabricated in a way that no single wire ends and sharp edges protrude, on which food residues might adhere, or no gaps between wire and frame, which are difficult to clean, can be formed, in which product residues can also accumulate. Further, the formation of cavities should be avoided for hygienical reasons. This problem can, however, be especially observed at the above-mentioned grid flaps, which are fabricated from sheet metal plates, wherein a grid is aligned between the sheet metal plates.
Furthermore, the known grid flaps are not suitable for a series production by machines and have to be produced individually by hand, which entails the disadvantage that the quality of the member depends on the skill and experience of the craftsman and can thus largely vary.